Java script help in Live Cycle Designer

Hi

Can you please let me know how to identify whether value in a decimal field has  decimal

if value has decimal, i need to ignore that value during summation.

Requirement is as follows

A table has 2 columns. Column 1 has a running number that can have values like 1, 1.1, 1.2, 2

Second column is amount. This can have decimals.

I need to total the amount only for main nos 1, 2.  Amount for rows having decimal should be ignored

code i use as part of  calculate

var fields = xfa.resolveNodes("Subform1.Table1.Row1[*]");

xfa.host.messageBox("fields length"+fields.length);

for(i=0 ; i<fields.length; i++) 

{

  c = xfa.resolveNode("Subform1.Table1.Row1[" + i +"].NF1[*]").rawValue;

how to check if c has decimal?

}

Thanks in advance

Ram